#include "Battery.h"

#define ADC1_DR_Address                ((uint32_t)0x4001244C)

__IO static uint16_t ADCConvertedValue;

void VoltageMeasureInit(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	ADC_InitTypeDef ADC_InitStructure;
	DMA_InitTypeDef DMA_InitStructure;

	/* ADCCLK = PCLK2/2 */
	RCC_ADCCLKConfig(RCC_PCLK2_Div2);
	/* Enable peripheral clocks ------------------------------------------------*/
	/* Enable DMA1 clock */
	RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

	/* Enable ADC1 and GPIOA clock */
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_GPIOA, ENABLE);

	/* Configure PA.04 (ADC Channel4) as analog input -------------------------*/
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
	GPIO_Init(GPIOA, &GPIO_InitStructure);

	/* DMA1 channel1 configuration ----------------------------------------------*/
	DMA_DeInit(DMA1_Channel1);
	DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;
	DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADCConvertedValue;
	DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
	DMA_InitStructure.DMA_BufferSize = 2;
	DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
	DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
	DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
	DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
	DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
	DMA_InitStructure.DMA_Priority = DMA_Priority_High;
	DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
	DMA_Init(DMA1_Channel1, &DMA_InitStructure);

	/* Enable DMA1 channel1 */
	DMA_Cmd(DMA1_Channel1, ENABLE);

	/* ADC1 configuration ------------------------------------------------------*/
	ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
	ADC_InitStructure.ADC_ScanConvMode = ENABLE;
	ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
	ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
	ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
	ADC_InitStructure.ADC_NbrOfChannel = 1;
	ADC_Init(ADC1, &ADC_InitStructure);

	/* ADC1 regular channel4 configuration */ 
	ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 1, ADC_SampleTime_55Cycles5);

	/* Enable ADC1 DMA */
	ADC_DMACmd(ADC1, ENABLE);

	/* Enable ADC1 */
	ADC_Cmd(ADC1, ENABLE);

	/* Enable ADC1 reset calibration register */
	ADC_ResetCalibration(ADC1);
	/* Check the end of ADC1 reset calibration register */
	while(ADC_GetResetCalibrationStatus(ADC1));

	/* Start ADC1 calibration */
	ADC_StartCalibration(ADC1);
	/* Check the end of ADC1 calibration */
	while(ADC_GetCalibrationStatus(ADC1));

	/* Start ADC1 Software Conversion */ 
	ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}

float GetSampleVoltage(void)
{
	return (((float)ADCConvertedValue * 3.3f) / 4096.0f);
}
